Vacuum Bag Sealing System and Method for Composite Parts

ABSTRACT

A method for vacuum bag sealing a composite part including: using a composite bagging sheet including a first sealing surface and a first interlocking strip coupled to the first sealing surface of the composite bagging sheet; joining the first interlocking strip with a second interlocking strip coupled to a second sealing surface; and forming a sealed vacuum bag around an uncured composite part positioned between the first sealing surface and the second sealing surface.

PRIORITY

This application claims priority from U.S. Ser. No. 14/153,797 filed onJan. 13, 2014, which claims priority from U.S. Ser. No. 61/894,175 filedon Oct. 22, 2013.

FIELD

The present disclosure is generally related to vacuum bags suitable forsealing a composite part on a curing tool and, more particularly, to avacuum bag sealing system and method for sealing a composite part on acuring tool while curing the composite part.

BACKGROUND

Composite parts are used for a variety of applications. For example manyparts of an aircraft such as wing planks, vertical and horizontalstabilizer skins, fuselage panels, and various other components are madeof composite structures. The composite parts are typically formed on amold that is mounted on a base plate. Layers of composite material areimpregnated with uncured resin and then laid up over the mold. A vacuumbag is then placed over the uncured composite material and sealed to theplate about the periphery. To cure the part, a vacuum is drawn frombetween the vacuum bag and the base plate and the entire assembly isplaced in an autoclave where the temperature and pressure are raised tocure the resin. After curing, the assembly is returned to roomtemperature and the vacuum bag is removed so that the cured compositepart may be removed from the mold.

Construction of the vacuum bag may be time consuming, expensive, andunreliable unless skilled personnel are assigned to the task. Requiringan airtight seal around the periphery of the composite part in order todraw and maintain a vacuum pressure further complicates the task.Requiring the fastening contact to be airtight may limit the types offastening and the types of vacuum bags that may be used and alsorequires that the fastening construction be done with careful skill.

Accordingly, those skilled in the art continue with research anddevelopment efforts in the field of vacuum bag sealing.

SUMMARY

In one embodiment, the disclosed vacuum bag sealing system includes acomposite bagging sheet, and at least one interlocking strip connectedto a surface of the composite bagging sheet, wherein the interlockingstrip is configured to join a first section of the composite baggingsheet to a second section of the composite bagging sheet to form asealed vacuum bag.

In another embodiment, the disclosed vacuum bag sealing system includesat least one first interlocking strip connected to a composite baggingsheet, and at least one second interlocking strip, wherein the firstinterlocking strip is configured to join the composite bagging sheet tothe second interlocking strip. The composite bagging sheet includes afirst section and a second section, the first interlocking strip isconnected to the first section and the second interlocking strip isconnected to the second section, and the first section and the secondsection are joined along the first interlocking strip and the secondinterlocking strip to form a sealed vacuum bag.

In another embodiment, the disclosed vacuum bag sealing system includesat least one first interlocking strip connected a composite baggingsheet, and at least one second interlocking strip, wherein the firstinterlocking strip is configured to join the composite bagging sheet tothe second interlocking strip. The second interlocking strip isconnected to a second composite bagging sheet, and the first compositebagging sheet and the second composite bagging sheet are joined alongthe first interlocking strip and the second interlocking strip to form asealed vacuum bag.

In another embodiment, the disclosed vacuum bag sealing system includesat least one first interlocking strip connected to a composite baggingsheet, and at least one second interlocking strip, wherein the firstinterlocking strip is configured to join the composite bagging sheet tothe second interlocking strip. The second interlocking strip isconnected to a surface of a composite forming tool, and the compositebagging sheet and the forming tool are joined along the firstinterlocking strip and the second interlocking strip to form a sealedvacuum bag.

In another embodiment, disclosed is a method for vacuum bag sealing, themethod includes steps of: (1) providing a composite bagging sheet, thecomposite bagging sheet including a first section and a second section;(2) providing at least one interlocking strip connected to a surface ofthe composite bagging sheet; (3) providing a mold; (4) placing acomposite part on the mold; and (5) joining the first section to thesecond section along the interlocking strip to form a sealed vacuum bagaround the mold and the composite part.

In another embodiment, disclosed is a method for vacuum bag sealing acomposite part, the method includes steps of: (1) using a compositebagging sheet including a sealing surface and an interlocking stripcoupled to the sealing surface of the composite bagging sheet; (2)folding the composite bagging sheet about a central fold line to form afirst section of the composite bagging sheet and a second section of thecomposite bagging sheet; (3) joining the first section of the compositebagging sheet and the second section of the composite bagging sheet withthe interlocking strip; and (4) forming a sealed vacuum bag around anuncured composite part positioned between a first portion of the sealingsurface and a second portion of the sealing surface.

In yet another embodiment, disclosed is a method for vacuum bag sealinga composite part, the method includes steps of: (1) using a compositebagging sheet including a first sealing surface and a first interlockingstrip coupled to the first sealing surface of the composite baggingsheet; (2) joining the first interlocking strip with a secondinterlocking strip coupled to a second sealing surface; and (3) forminga sealed vacuum bag around an uncured composite part positioned betweenthe first sealing surface and the second sealing surface.

Other embodiments of the disclosed vacuum bag sealing system and methodwill become apparent from the following detailed description, theaccompanying drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plan view of one embodiment of the disclosed vacuum bagsealing system;

FIG. 2 is a side elevational view, in section, of one embodiment of thevacuum bag formed by the disclosed vacuum bag sealing system;

FIG. 3 is a broken away perspective view of a composite part formingtool utilizing the disclosed vacuum bag sealing system;

FIG. 4 is a side elevation view, in section, of a composite part formingtool utilizing another embodiment of the disclosed vacuum bag sealingsystem;

FIG. 5 is a side elevation view, in section, of a composite part formingtool utilizing another embodiment of the disclosed vacuum bag sealingsystem;

FIG. 6 is a side elevational view, in section, of one embodiment of theinterlocking strip of the disclosed vacuum bag sealing system;

FIG. 7 is a side elevational view, in section, of interlocked sectionsof the interlocking strip of FIG. 6;

FIG. 8 is a side elevational view, in section of another embodiment ofthe interlocking strip of the disclosed vacuum bag sealing system;

FIG. 9 is a flow chart depicting one embodiment of the disclosed methodfor vacuum bag sealing;

FIG. 10 is a flow chart depicting another embodiment of the disclosedmethod for vacuum bag sealing;

FIG. 11 is a flow chart depicting yet another embodiment of thedisclosed method for vacuum sealing;

FIG. 12 is flow diagram of an aircraft production and servicemethodology; and

FIG. 13 is a block diagram of an aircraft.

DETAILED DESCRIPTION

The following detailed description refers to the accompanying drawings,which illustrate specific embodiments of the disclosure. Otherembodiments having different structures and operations do not departfrom the scope of the present disclosure. Like reference numerals mayrefer to the same element or component in the different drawings.

Referring to FIGS. 1 and 2, one embodiment of the disclosed vacuum bagsealing system, generally designated 10, for composite parts may includea composite bagging sheet 12 having one or more interlocking strips 14.The composite bagging sheet 12 may be a crinkled bag film, nylon, apolymeric material, silicone rubber, or any other type of material thatis suitable for vacuum sealing applications. The composite bagging sheet12 may include a first surface 16 (e.g., an exposed surface), a secondsurface 18 (e.g., a sealing surface) opposite the first surface 16, anda perimeter edge 20.

As illustrated in FIG. 1, in an example construction, the compositebagging sheet 12 may be generally elongated and rectangular in shapehaving a first edge 22 (e.g., a first lengthwise edge), a second edge 24(e.g., a second lengthwise edge) laterally spaced apart from the firstedge 22, a third edge 26 (e.g., a first widthwise edge) extendingbetween the first edge 22 and the second edge 24, and a fourth edge 28(e.g., a second widthwise edge) extending between the first edge 22 andthe second edge 24 and longitudinally spaced apart from the third edge26. In other example constructions, the composite bagging sheet 12 mayhave other shapes and configurations, such as circular, ovular, orsquare.

One or more interlocking strips 14 may be connected to the secondsurface 18 of the composite bagging sheet 12. The interlocking strip 14may be fabricated from any material suitable for high temperatures(e.g., up to approximately 850° C.). The interlocking strips 14 may bebonded to the composite bagging sheet 12 by any suitable method. Forexample, the interlocking strips 14 may be heat welded to the secondsurface 18 of the composite bagging sheet 12. As another example, theinterlocking strips 14 may be adhered to the second surface 18 of thecomposite bagging sheet 12, such as with sealing tape or an adhesivecompound.

The interlocking strip 14 may be positioned proximate (e.g., at or near)the perimeter edge 20 of the composite bagging sheet 12. Alternatively,the interlocking strip 14 may be spaced away from the perimeter edge 20of the composite bagging sheet 12. Alternatively, the interlocking strip14 may extend beyond the perimeter edge 20 of the composite baggingsheet 12. In an example construction, the interlocking strip 14 mayextend around a portion of the perimeter edge 20 of the compositebagging sheet 12. In another example construction, the interlockingstrip 14 may extend around the entire perimeter edge 20 of the compositebagging sheet 12.

For example, a single interlocking strip 14 may extend around the entireperimeter edge 20 of the composite bagging sheet 12. As another example,one or more first interlocking strips 14 a may be positioned proximatethe first edge 22, one or more second interlocking strips 14 b may bepositioned proximate the second edge 24, one or more third interlockingstrips 14 c may be positioned proximate the third edge 26, and one ormore fourth interlocking strips 14 d may be positioned proximate thefourth edge 28. If more than one interlocking strip 14 is used, allintersecting end edges of adjacent interlocking strips 14 may be bondedor otherwise connected together to form a substantially airtight sealbetween adjacent interlocking strips 14.

Referring to FIG. 2, the interlocking strip 14 may be configured to joinsections of the composite bagging sheet 12 together to form asubstantially airtight sealed vacuum bag 30. For example, theinterlocking strip 14 may include a cross-sectional shape configured tointerlock (e.g., snap lock) any portion of the interlocking strip 14 toany other portion of the interlocking strip 14. The vacuum bag 30 formedby joining sections of the composite bagging sheet 12 may include aninternal volume 31 suitable to contain a composite forming tool 40 (FIG.3).

For example, the vacuum bag 30 may be formed by folding the vacuum bagsheet 12 about the first edge 22 and the second edge 24 such that thesecond surface 18 of a first section 32 of the vacuum bag sheet 12 facesthe second surface 18 of a second section 34 of the vacuum bag sheet 12(e.g., folding the vacuum bag sheet 12 in half laterally). The thirdinterlocking strip 14 c may engage the fourth interlocking strip 14 d. Afirst section 14 a′ of the first interlocking strip 14 a (e.g., asection of the first interlocking strip 14 a extending from a fold line36 (FIG. 1) to the third interlocking strip 14 c) may engage a secondsection 14 a″ of the first interlocking strip 14 a (e.g., a section ofthe first interlocking strip 14 a extending from the fold line 36 to thefourth interlocking strip 14 d). A first section 14 b′ of the secondinterlocking strip 14 b (e.g., a section of the second interlockingstrip 14 b extending from the fold line 36 to the third interlockingstrip 14 c) may engage a second section 14 b″ of the second interlockingstrip 14 b (e.g., a section of the second interlocking strip 14 bextending from the fold line 36 to the fourth interlocking strip 14 d).Upon a compression force F being applied to the engaged interlockingstrips 14 (e.g., engaged third interlocking strip 14 c and fourthinterlocking strip 14 d, engaged sections of the first interlockingstrip 14 a, and engaged sections of the second interlocking strip 14 b),the interlocking strips 14 may lock together to form a substantiallyairtight seal around the perimeter edge 20 of the composite baggingsheet 12.

As another example, the vacuum bag 30 may be formed by folding thevacuum bag sheet 12 about the third edge 26 and the fourth edge 28 suchthat the second surface 18 of a first section 32 of the vacuum bag sheet12 faces the second surface 18 of a second section 34 of the vacuum bagsheet 12 (e.g., folding the vacuum bag sheet 12 in half longitudinally)(not shown). The first interlocking strip 14 a may engage the secondinterlocking strip 14 b. A first section 14 c′ of the third interlockingstrip 14 c (e.g., a section of the third interlocking strip 14 cextending from a fold line 37 to the first interlocking strip 14 a) mayengage a second section 14 c″ of the third interlocking strip 14 c(e.g., a section of the third interlocking strip 14 c extending from thefold line to the second interlocking strip 14 b). A first section 14 d′of the fourth interlocking strip 14 d (e.g., a section of the fourthinterlocking strip 14 d extending from the fold line to the firstinterlocking strip 14 a) may engage a second section 14 d″ of the fourthinterlocking strip 14 d (e.g., a section of the fourth interlockingstrip 14 d extending from the fold line to the second interlocking strip14 b). Upon a compression force F being applied to the engagedinterlocking strips 14 (e.g., engaged first interlocking strip 14 a andsecond interlocking strip 14 b, engaged sections of the thirdinterlocking strip 14 c, and engaged sections of the fourth interlockingstrip 14 d), the interlocking strips 14 may lock together to form asubstantially airtight seal around the perimeter edge 20 of thecomposite bagging sheet 12.

FIG. 3 illustrates a composite part 38 formed on a forming tool 40utilizing the disclosed vacuum bag sealing system 10. The forming tool40 may include a solid surface in the form of a base plate 42. Althoughthe base plate 42 is shown having a flat rectangular shape, thoseskilled in the art will appreciate that the base plate 42 may have acomplex, three-dimensional shape and/or contour.

The composite bagging sheet 12 may be laid over the base plate 42. Forexample, the first section 32 of the composite bagging sheet 12 may beplaced over the base plate 42 such that the second surface 18 faces awayfrom the base plate 42.

A mold 44 may be mounted on the base plate 42 over the second section 34of the composite bagging sheet 12. The mold 42 may include any regularor irregular shape having the shape of the composite part 38 to beformed. For example, the mold 44 is shown having a contoured surfaceincorporating the desired shape of the composite part 38 to be formed.

The composite part 38 may be formed from any suitable compositematerial, for example sheets or plies of woven or unidirectionalfilamentary material. The plies of composite material may be laid overthe mold 44. The plies of composite material may generally bepre-impregnated with an uncured resin and then placed on the mold 44.

Optionally, bleeder and/or breather cloth (not shown) may be used asrequired.

The composite bagging sheet 12 may be folded (e.g., about the fold line36, as shown in FIG. 1) to place the second section 34 of the compositebagging sheet 12 over the mold 44 and the plies of composite materialforming the composite part 38 (e.g., with the second surface 18 facingthe base plate 42). A portion of the interlocking strip 14 disposed onthe second surface 18 of the of the composite bagging sheet 12 may bealigned with and engage a portion of the interlocking strip 14 disposedon the second surface 18 of the second section 34 to form the vacuum bag30 having a substantially airtight seal (e.g., in response to thecompression force F).

A vacuum pressure may be drawn on the plies of composite materialforming the composite part 38 and the mold 44 with the aid of the sealedvacuum bag 30. For example, a vacuum probe base 46 may be placed insidethe vacuum bag 30 (e.g., positioned between the first section 32 and thesecond section 34 of the composite bagging sheet 12 prior to joining theinterlocking strip 14). A small aperture (not shown) may be cut in thecomposite bag material 12 and aligned with the vacuum probe base 46. Avacuum fitting 48 may be connected to the vacuum probe base 46. Thevacuum fitting 48 may include a gasket configured to seal the compositebagging sheet 12 around the connection of the vacuum fitting 48 and thevacuum probe base 46. The vacuum fitting 48 may be connected to a vacuumsource 50 configured to draw the vacuum pressure on the plies ofcomposite material forming the composite part 38 and the mold 44 sealedwithin the vacuum bag 30.

An entire assembly, including the mold 42, the composite part 38, andthe vacuum bag 30 may then placed in an autoclave or oven in which thelayup is cured through the application of further pressure at anelevated temperature. After removal from the autoclave and cooling downto room temperature, the vacuum bag 30 may be unsealed (e.g., the firstsection 32 may be removed from the second section 34) and the formedcomposite part 38 may be removed from the mold 44.

Optionally, at least one lengthwise pleat (not shown) may be formed inthe composite bagging sheet 2 between the perimeter edges 20 (e.g.,between the first edge 22 and the second edge 24) according to theknowledge of those skilled in the art. One or multiple lengthwise pleatsmay be disposed in generally parallel relationship with respect to eachother and a longitudinal axis of the composite bagging sheet 12. Thoseskilled in the art will appreciated that the presence of one or morepleats in the composite bagging sheet 12 may enable steering of thevacuum bag 30 around a curvature in the composite part 38 or along acurved track (not shown) as the vacuum bag 30 is applied over thecomposite part 38.

Those skilled in the art will appreciate that depending upon thematerial of the composite bagging sheet 12, the composite bagging sheet12 may be reused to form a vacuum bag 30 for additional compositeforming processes. Additionally, the vacuum bag 30 formed by thecomposite bagging sheet 12 and the interlocking strip 14 may be suitablefor a variety of alternative sealing applications.

Referring to FIG. 4, another embodiment of the disclosed vacuum bagsealing system, generally designated 60, may include a first compositebagging sheet 52 having an interlocking strip 54 and a second compositebagging sheet 56 having an interlocking strip 58. Each composite baggingsheet 52, 56 may be substantially similar to the composite bagging sheet12 described above (FIG. 1). Each interlocking strip 54, 58 may besubstantially similar to the interlocking strip 14 described herein(FIG. 6). For example, the first composite bagging sheet 52 may includeone or more first interlocking strips 54 bonded to a second surface 62(e.g., a sealing surface) proximate a perimeter edge and the secondcomposite bagging sheet 56 may include one or more second interlockingstrips 58 bonded to a second surface 64 (e.g., a sealing surface)proximate a perimeter edge. The first composite bagging sheet 52 and thesecond composite bagging sheet 56 may be substantially equal in shapeand dimensions.

As illustrated in FIG. 4, the composite part 38 may be formed on theforming tool 40 utilizing the disclosed vacuum bag sealing system 60.The forming tool 40 may include the base plate 42 and the mold 44. Thefirst composite bagging sheet 52 may be laid over the base plate 42 withthe second surface 62 facing away from the base plate 42.

The mold 44 may be mounted on the base plate 42 over the first compositebagging sheet 52. The plies of composite material forming the compositepart 38 may be laid over the mold 44. Optionally, bleeder and/orbreather cloth (not shown) may be used as required.

The second composite bagging sheet 56 may be placed over the mold 44 andthe plies of composite material forming the composite part 38. Theinterlocking strip 54 of the first composite bagging sheet 52 may bealigned with and engage the interlocking strip 58 of the secondcomposite bagging sheet 56 to form a vacuum bag 66 defining an internalvolume 68 and having a substantially airtight seal (e.g., in response tothe compression force F).

A vacuum pressure may be drawn on the plies of composite materialforming the composite part 38 and the mold 44 with the aid of the sealedvacuum bag 66. An entire assembly, including the mold 42, the compositepart 38, and the vacuum bag 66 may then be placed in an autoclave inwhich the layup is cured through the application of further pressure atan elevated temperature. After removal from the autoclave and coolingdown to room temperature, the vacuum bag 66 may be unsealed (e.g., thesecond composite bagging sheet 64 may be removed from the firstcomposite bagging sheet 62) and the formed composite part 38 may beremoved from the mold 44.

Referring to FIG. 5, another embodiment of the disclosed vacuum bagsealing system, generally designated 70, may include a composite baggingsheet 72 having an interlocking strip 74. The composite bagging sheet 72may be substantially similar to the composite bagging sheet 12 describedabove (FIG. 1). For example, the composite bagging sheet 72 may includeone or more interlocking strips 74 bonded to a second surface 76 (e.g.,a sealing surface) proximate a perimeter edge. The interlocking strip 74may be substantially similar to the interlocking strip 14 describedherein (FIG. 6).

As illustrated in FIG. 5, the composite part 38 may be formed on theforming tool 40 utilizing the disclosed vacuum bag sealing system 70.The forming tool 40 may include the base plate 42 and the mold 44. Themold 44 may be mounted on the base plate 42. The plies of compositematerial forming the composite part 38 may be laid over the mold 44.Optionally, bleeder and/or breather cloth (not shown) may be used asrequired.

One or more second interlocking strips 78 may be bonded to a surface 80of the base plate 42. The second interlocking strip 78 may besubstantially similar to the interlocking strip 14 described herein(FIG. 6). For example, the second interlocking strip 78 may be bonded tothe surface 80 of the base plate 42 proximate a perimeter edge 82 of thebase plate 42. The surface 80 of the base plate 42 to which the secondinterlocking strip 78 is bonded may be flat or contoured.

The composite bagging sheet 72 may be placed over the mold 44 and theplies of composite material forming the composite part 38. Theinterlocking strip 74 of the composite bagging sheet 72 may be alignedwith and engage the second interlocking strip 78 bonded to the surface80 of the base plate 42 to form a vacuum bag 83 defining an internalvolume 85 and having a substantially airtight seal (e.g., in response tothe compression force F).

A vacuum pressure may be drawn on the plies of composite materialforming the composite part 38 and the mold 44 with the aid of the sealedvacuum bag 83. An entire assembly, including the mold 42, the compositepart 38, and the vacuum bag 83 may then be placed in an autoclave inwhich the layup is cured through the application of further pressure atan elevated temperature. After removal from the autoclave and coolingdown to room temperature, the vacuum bag 83 may be unsealed (e.g., thecomposite bagging sheet 72 may be removed from the base plate 42) andthe formed composite part 38 may be removed from the mold 44.

Referring to FIGS. 6 and 7, the interlocking strip 14 may include across-sectional shape configured to join a section of the interlockingstrip 14 with another section of interlocking strip 14 (e.g., the thirdinterlocking strip 14 c joined to the fourth interlocking strip 14 d ora first portion of the first interlocking strip 14 a joined to a secondportion of the first interlocking strip 14 a, as shown in FIG. 1). Theinterlocking strip 14 may include any cross-sectional shape orconfiguration suitable to allow opposed sections of the interlockingstrip 14 (e.g., on opposite sides of the composite bagging sheet 12 orthe same side of the composite bagging sheet 12) to engage and coupletogether or interlock and form a substantially airtight seal betweeninterlocked sections of the interlocking strip 14 and form the vacuumbag 30.

For example, as illustrated in FIG. 6, one embodiment of theinterlocking strip 14 may include an elongated coupling structure 84extending substantially between perimeter edges 20 of the compositebagging sheet 12 (FIG. 1). The coupling structure 84 may be configuredso that once coupled together with another coupling structure 84, theinterlocking strip 14 cannot be easily pulled apart or uncoupled, thusforming a substantially airtight seal.

In an example construction, the coupling structure 84 may include a head86 and a stem 88. The stem 88 may extend outward from a base 92. Thebase 92 may be bonded (e.g., heat welded or adhered) to the secondsurface 18 of the composite bagging sheet 12 (or the surface 80 of thebase plate 42) about a bonding surface 102. A free end of the stem 88may define the head 86. The head 86 may include at least one outwardlyextending hook 94, for example, the head 86 may include a pair ofoppositely disposed and outwardly extending hooks 94. For example, thehook 94 may extend substantially perpendicularly from the free end ofthe stem 88. As another example, the hook 94 may extend at a non-zeroangle other than perpendicular from the free end of the stem 88.

As illustrated in FIG. 7, the hook 94 of a first section 98 of theinterlocking strip 14 may be configured to engage and interlock withcorresponding hook 94 of a second section 100 of the interlocking strip14. For example and in reference to FIG. 1, the hook 94 of the thirdinterlocking strip 14 c (e.g., the first section 98) may cooperate andinterlock with the hook 94 of the fourth interlocking strip 14 d (e.g.,the second section 100) when the composite bagging sheet 12 is foldedabout the fold line 36. As another example, the hook 94 of the firstsection 14 a′ of the first interlocking strip 14 a (e.g., the firstsection 98) may cooperate and interlock with hook 94 of the secondsection 14 a″ of the first interlocking strip 14 a (e.g., the secondsection 100) when the composite bagging sheet 12 is folded about thefold line 36.

Optionally, one or more ribs 90 may extend adjacent to the stem 88. Thestem 88 and the ribs 90 may extend outward from the common base 92. Theribs 90 may be configured to engage (e.g., contact) a hook 94 of thehead 86 opposite the hook 94 engaged with a hook 94 of a cooperativelycoupled head 86. For example, the rib 90 and the coupling structure 84may form a mouth 104 configured to receive the head 86 of acooperatively opposed coupling structure 84.

Referring to FIG. 8, another embodiment of the interlocking strip 14 mayinclude more than one elongated coupling structure 84 extendingsubstantially between perimeter edges 20 of the composite bagging sheet12 (FIG. 1). Adjacent coupling structures 84 may be substantiallyparallel and spaced apart a suitable distance to receive the head 86 ofa cooperatively opposed coupling structure 84. For example, adjacentcoupling structures 84 of the first section 98 of the interlocking strip14 may define a groove 106 configured to receive the head 86 of acooperatively opposed coupling structure 84 of the second section 100 ofthe interlocking strip 14. Thus, the hooks 94 of adjacent couplingstructures 84 (e.g., pairs of facing hooks 94) of the first section 98of the interlocking strip 14 may engage and interlock with opposed hooks94 of the head 86 of the cooperatively opposed coupling structure 84 ofthe second section 100 of the interlocking strip 14.

In another embodiment, the interlocking strip 14 may include anelongated, generally inverted L-shaped coupling structure (not shown)extending substantially between perimeter edges 20 of the compositebagging sheet 12. In another embodiment, the interlocking strip 14 mayinclude an elongated, generally inverted J-shaped coupling structure(not shown) extending substantially between perimeter edges 20 of thecomposite bagging sheet 12. In yet another embodiment, the interlockingstrip 14 may include an elongated, generally T-shaped coupling structure(not shown) extending substantially between perimeter edges 20 of thecomposite bagging sheet 12. Other configurations of the interlockingstrip 14 and shapes (e.g., cross-sectional shapes) of the couplingstructure 84 are also contemplated.

Those skilled in the art will appreciate that the configuration of theinterlocking strip 14 (e.g., the shape of the coupling structure 84) maybe the same or may vary along the length of one or more of the perimeteredges 20 of the composite bagging sheet 12 to facilitate connection withanother interlocking strip 14. For example and in reference to FIG. 1,the third interlocking strip 14 c may include a configuration suitableto cooperate and interlock with a configuration of the fourthinterlocking strip 14 d when the composite bagging sheet 12 is foldedabout the fold line 36. As another example, the first interlocking strip14 may include the first section 14 a′ having a configuration suitableto cooperate and interlock with a configuration of the second section 14a″ when the composite bagging sheet 12 is folded about the fold line 36,where the configuration of the first section 14 a′ is different than theconfiguration of the second section 14 a″.

In an example implementation, a manufacturer of the composite baggingsheet 12 may bond the interlocking strip 14 to the composite baggingsheet 12 (FIG. 1). In another example implementation, a manufacturer ofthe composite part 38 (FIG. 3) may bond the interlocking strip 14 to thecomposite bagging sheet 12 and/or the forming tool 40 (e.g., the surface80 of the base plate 42, as illustrated in FIG. 5) prior to a vacuumbagging composite manufacturing process. For example, the interlockingstrip 14 may take the form of a dispensable elongated strip includingthe base 92 and the coupling structure 84 (FIG. 6), which can be cut tolength and connected directly to an appropriate location on thecomposite bagging sheet 12 and/or the forming tool 40.

Referring to FIG. 9 and in reference to FIG. 3, disclosed is oneembodiment of a method, generally designated 200, for vacuum bag sealingfor composite parts. As shown at block 202, a composite bagging sheet 12may be provided. As shown at block 204, at least one interlocking strip14 may be provided along a perimeter edge 20 (FIG. 1) of the compositebagging sheet 12. As shown at block 206, a first section 32 of thecomposite bagging sheet 12 may be placed on a base plate 42 of a formingtool 40. As shown at block 208, a mold 44 may be mounted to the baseplate 42 over top of the first section 32 of the composite bagging sheet12. As shown at block 210, composite material forming the composite part38 may be placed on the mold 44. As shown at block 212, the compositebagging sheet 12 may be folded over such that a second section 34 of thecomposite bagging sheet 12 is placed over the mold 44 and the compositepart 38. As shown at block 214, a first section 98 (FIG. 7) of theinterlocking strip 14 of the second section 34 of the composite baggingsheet 12 may be aligned and engaged with a second section 100 (FIG. 7)of the interlocking strip 14 of the first section 32 of the compositebagging sheet 12. As shown at block 216, the first section 32 of thecomposite bagging sheet 12 may be joined to the second section 34 of thecomposite bagging sheet 12 by interlocking the first section 98 of theinterlocking strip 14 with the second section 100 of the interlockingstrip 14 to form a sealed vacuum bag 30 around the mold 42 and thecomposite part 38. As shown at block 218, a vacuum may be drawn on thecomposite part 38 within the vacuum bag 30. As shown at block 220, thecomposite part 38 may be cured. As shown at block 222, the vacuum bag 30may be unsealed by uncoupling the interlocking strip 14 of the secondsection 34 of the composite bagging sheet 12 from the interlocking strip14 of the first section 32 of the composite bagging sheet 12. As shownat block 224, the cured composite part 38 may be removed from the mold44.

Referring to FIG. 10 and in reference to FIG. 4, disclosed is anotherembodiment of a method, generally designated 300, for vacuum bag sealingfor composite parts. As shown at block 302, a first composite baggingsheet 52 may be provided. As shown at block 304, at least one firstinterlocking strip 54 may be provided along a perimeter edge of thefirst composite bagging sheet 52. As shown at block 306, a secondcomposite bagging sheet 56 may be provided. As shown at block 308, atleast one second interlocking strip 58 may be provided along a perimeteredge of the second composite bagging sheet 56. As shown at block 310,the first composite bagging sheet 52 may be placed on a base plate 42 ofa forming tool 40. As shown at block 312, a mold 44 may be mounted tothe base plate 42 over top of the first composite bagging sheet 52. Asshown at block 314, composite material forming the composite part 38 maybe placed on the mold 44. As shown at block 316, the second compositebagging sheet 56 may be placed over the mold 44 and the composite part38. As shown at block 318, the first interlocking strip 54 of the firstcomposite bagging sheet 52 may be aligned and engaged with a secondinterlocking strip 58 of the second composite bagging sheet 56. As shownat block 320, the first composite bagging sheet 52 may be joined to thesecond composite bagging sheet 56 by interlocking the first interlockingstrip 54 with the second interlocking strip 58 to form a sealed vacuumbag 66 around the mold 42 and the composite part 38. As shown at block322, a vacuum may be drawn on the composite part 38 within the vacuumbag 66. As shown at block 324, the composite part 38 may be cured. Asshown at block 326, the vacuum bag 30 may be unsealed by uncoupling thesecond interlocking strip 58 of the second composite bagging sheet 56from the first interlocking strip 54 of the first composite baggingsheet 52. As shown at block 328, the cured composite part 38 may beremoved from the mold 44.

Referring to FIG. 11 and in reference to FIG. 5, disclosed is yetanother embodiment of a method, generally designated 400, for vacuum bagsealing for composite parts. As shown at block 402, a composite baggingsheet 72 may be provided. As shown at block 404, at least one firstinterlocking strip 74 may be provided along a perimeter edge of thecomposite bagging sheet 72. As shown at block 406, at least one secondinterlocking strip 78 may be provided on along a perimeter edge of abase plate 42 of a forming tool 40. As shown at block 408, a mold 44 maybe mounted to the base plate 42. As shown at block 410, compositematerial forming the composite part 38 may be placed on the mold 44. Asshown at block 412, the composite bagging sheet 72 may be placed overthe mold 44 and the composite part 38. As shown at block 414, the firstinterlocking strip 74 of the composite bagging sheet 72 may be alignedand engaged with the second interlocking strip 78 of the base plate 42.As shown at block 416, the composite bagging sheet 72 may be joined tothe base plate 42 by interlocking the first interlocking strip 74 withthe second interlocking strip 78 to form a sealed vacuum bag 83 aroundthe mold 42 and the composite part 38. As shown at block 418, a vacuummay be drawn on the composite part 38 within the vacuum bag 83. As shownat block 420, the composite part 38 may be cured. As shown at block 422,the vacuum bag 83 may be unsealed by uncoupling the first interlockingstrip 74 from the second interlocking strip 78. As shown at block 424,the cured composite part 38 may be removed from the mold 44.

Examples of the disclosure may be described in the context of anaircraft manufacturing and service method 500, as shown in FIG. 12, andan aircraft 502, as shown in FIG. 13. During pre-production, theaircraft manufacturing and service method 500 may include specificationand design 504 of the aircraft 502 and material procurement 506. Duringproduction, component/subassembly manufacturing 508 and systemintegration 510 of the aircraft 502 takes place. Thereafter, theaircraft 502 may go through certification and delivery 512 in order tobe placed in service 514. While in service by a customer, the aircraft502 is scheduled for routine maintenance and service 516, which may alsoinclude modification, reconfiguration, refurbishment and the like.

Each of the processes of method 500 may be performed or carried out by asystem integrator, a third party, and/or an operator (e.g., a customer).For the purposes of this description, a system integrator may includewithout limitation any number of aircraft manufacturers and major-systemsubcontractors; a third party may include without limitation any numberof venders, subcontractors, and suppliers; and an operator may be anairline, leasing company, military entity, service organization, and soon.

As shown in FIG. 13, the aircraft 502 produced by example method 500 mayinclude an airframe 518 with a plurality of systems 520 and an interior522. Examples of high-level systems 520 include one or more of apropulsion system 524, an electrical system 526, a hydraulic system 528,and an environmental system 530. Any number of other systems may beincluded. Although an aerospace example is shown, the principles of theinvention may be applied to other industries, such as the automotiveindustry.

Apparatus and methods embodied herein may be employed during any one ormore of the stages of the production and service method 500. Forexample, components or subassemblies corresponding tocomponent/subassembly manufacturing 508 may be fabricated ormanufactured in a manner similar to components or subassemblies producedwhile the aircraft 502 is in service. Also, one or more apparatusexamples, method examples, or a combination thereof may be utilizedduring component/subassembly manufacturing 508 and/or system integration510, for example, by substantially expediting assembly of or reducingthe cost of an aircraft 502. Similarly, one or more of apparatusexamples, method examples, or a combination thereof may be utilizedwhile the aircraft 502 is in service, for example and withoutlimitation, to maintenance and service 516.

Although various embodiments of the disclosed vacuum bag sealing systemand method have been shown and described, modifications may occur tothose skilled in the art upon reading the specification. The presentapplication includes such modifications and is limited only by the scopeof the claims.

What is claimed is:
 1. A method for vacuum bag sealing comprising:providing a composite bagging sheet, said composite bagging sheetcomprising a first section and a second section; providing at least oneinterlocking strip connected to a surface of said composite baggingsheet; providing a mold; placing a composite part on said mold; andjoining said first section to said second section along saidinterlocking strip to form a sealed vacuum bag around said mold and saidcomposite part.
 2. The method of claim 1 further comprising: drawing avacuum within said vacuum bag; and curing said composite part.
 3. Themethod of claim 1 further comprising: folding said composite baggingsheet about a central fold line to form said first section of saidcomposite bagging sheet and said second section of said compositebagging sheet; and interlocking a first section of said interlockingstrip, associated with said first section of said composite baggingsheet, and a second section of said interlocking strip, associated withsaid second section of said composite bagging sheet, together.
 4. Themethod of claim 1 wherein: said composite bagging sheet furthercomprises a perimeter edge; and said interlocking strip extends along anentirety of said perimeter edge.
 5. The method of claim 1 wherein: saidinterlocking strip comprises: a stem extending from said surface of saidcomposite bagging sheet; and a head disposed at a free end of said stem;and said method further comprises interlocking said head of said firstportion of said coupling structure with said head of said second portionof said coupling structure.
 6. A method for vacuum bag sealing acomposite part comprising: using a composite bagging sheet comprising asealing surface and an interlocking strip coupled to said sealingsurface of said composite bagging sheet; folding said composite baggingsheet about a central fold line to form a first section of saidcomposite bagging sheet and a second section of said composite baggingsheet; joining said first section of said composite bagging sheet andsaid second section of said composite bagging sheet with saidinterlocking strip; and forming a sealed vacuum bag around an uncuredcomposite part positioned between a first portion of said sealingsurface and a second portion of said sealing surface.
 7. The method ofclaim 6 further comprising: drawing a vacuum within said sealed vacuumbag; and curing said uncured composite part to form a cured compositepart.
 8. The method of claim 6 wherein said interlocking strip comprisesa coupling structure.
 9. The method of claim 8 further comprisinginterlocking a first portion of said coupling structure forming saidfirst section of said interlocking strip with a second portion of saidcoupling structure forming said second section of said interlockingstrip.
 10. The method of claim 9 wherein said coupling structurecomprises: a stem extending from said surface of said composite baggingsheet; and a head disposed at a free end of said stem.
 11. The method ofclaim 10 further comprising interlocking said head of said first portionof said coupling structure with said head of said second portion of saidcoupling structure.
 12. The method of claim 10 wherein said couplingstructure further comprises a base bonded to said sealing surface ofsaid composite bagging sheet.
 13. The method of claim 6 wherein saidinterlocking strip comprises a plurality of elongated couplingstructures arranged parallel to each other.
 14. The method of claim 13further comprising interlocking a first portion of said plurality ofcoupling structures forming said first section of said interlockingstrip with a second portion of said plurality of coupling structuresforming said second section of said interlocking strip.
 15. The methodof claim 14 wherein each one of said plurality of coupling structurescomprises: a stem extending from said surface of said composite baggingsheet; and a head disposed at a free end of said stem.
 16. The method ofclaim 15 further comprising interlocking one head of said first portionof said plurality of coupling structures forming said first section ofsaid interlocking strip with an adjacent pair of heads of said secondportion of said plurality of coupling structures forming said secondsection of said interlocking strip.
 17. A method for vacuum bag sealinga composite part comprising: using a composite bagging sheet comprisinga first sealing surface and a first interlocking strip coupled to saidfirst sealing surface of said composite bagging sheet; joining saidfirst interlocking strip with a second interlocking strip coupled to asecond sealing surface; and forming a sealed vacuum bag around anuncured composite part positioned between said first sealing surface andsaid second sealing surface.
 18. The method of claim 17 wherein saidsecond sealing surface is formed by a surface of another compositebagging sheet.
 19. The method of claim 17 wherein said second sealingsurface is formed by a surface of a composite forming tool.
 20. Themethod of claim 19 wherein: said composite bagging sheet is configuredto be folded about a central fold line to form a first section of saidcomposite bagging sheet and a second section of said composite baggingsheet; said first sealing surface is formed by said first section ofsaid composite bagging sheet; and said second sealing surface is formedby said second section of said composite bagging sheet.